55480021 has 4 divisors (see below), whose sum is σ = 55514412. Its totient is φ = 55445632.

The previous prime is 55480013. The next prime is 55480063. The reversal of 55480021 is 12008455.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26471025 + 29008996 = 5145^2 + 5386^2 .

It is a cyclic number.

It is not a de Polignac number, because 55480021 - 2³ = 55480013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55480081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14650 + ... + 18043.

It is an arithmetic number, because the mean of its divisors is an integer number (13878603).

Almost surely, 2^55480021 is an apocalyptic number.

It is an amenable number.

55480021 is a deficient number, since it is larger than the sum of its proper divisors (34391).

55480021 is a wasteful number, since it uses less digits than its factorization.

55480021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34390.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 55480021 is about 7448.4911894960. The cubic root of 55480021 is about 381.3984047885.

Adding to 55480021 its reverse (12008455), we get a palindrome (67488476).

The spelling of 55480021 in words is "fifty-five million, four hundred eighty thousand, twenty-one".